[gegl] tests: Add test case for linear shift

[Daniel Sabo <daniels src gnome org>]

commit b87a98110dd8b62b75c63aea0c5f339c46861d2e
Author: Daniel Sabo <DanielSabo gmail com>
Date:   Mon Sep 9 18:01:28 2013 -0700

    tests: Add test case for linear shift

 tests/buffer/reference/linear_shift.buf |    8 +++
 tests/buffer/tests/linear_shift.c       |   91 +++++++++++++++++++++++++++++++
 2 files changed, 99 insertions(+), 0 deletions(-)
---
diff --git a/tests/buffer/reference/linear_shift.buf b/tests/buffer/reference/linear_shift.buf
new file mode 100644
index 0000000..9b656af
--- /dev/null
+++ b/tests/buffer/reference/linear_shift.buf
@@ -0,0 +1,8 @@
+Test: linear_shift
+▛▀▀▀▀▀▜
+▌░░▒░░▐
+▌░░▒░░▐
+▌▒▒█▒▒▐
+▌░░▒░░▐
+▌░░▒░░▐
+▙▄▄▄▄▄▟
diff --git a/tests/buffer/tests/linear_shift.c b/tests/buffer/tests/linear_shift.c
new file mode 100644
index 0000000..f988113
--- /dev/null
+++ b/tests/buffer/tests/linear_shift.c
@@ -0,0 +1,91 @@
+TEST ()
+{
+  GeglBuffer         *out;
+  gint                i;
+  GeglBuffer         *linear_a;
+  GeglBuffer         *linear_b;
+  GeglBuffer         *linear_c;
+  GeglBuffer         *linear_d;
+  gfloat             *linear_data;
+  GeglBufferIterator *iter;
+  GeglRectangle       out_extent = {-1, -1, 5, 5};
+
+  test_start();
+
+  linear_data = malloc (sizeof(float) * 3 * 3);
+
+  for (i = 0; i < 3 * 3; ++i)
+    linear_data[i] = 0.25;
+
+  linear_a = gegl_buffer_linear_new_from_data (linear_data,
+                                               babl_format ("Y float"),
+                                               GEGL_RECTANGLE(-1, -1, 3, 3),
+                                               GEGL_AUTO_ROWSTRIDE,
+                                               NULL,
+                                               NULL);
+
+  linear_b = gegl_buffer_linear_new_from_data (linear_data,
+                                               babl_format ("Y float"),
+                                               GEGL_RECTANGLE(1, -1, 3, 3),
+                                               GEGL_AUTO_ROWSTRIDE,
+                                               NULL,
+                                               NULL);
+
+  linear_c = gegl_buffer_linear_new_from_data (linear_data,
+                                               babl_format ("Y float"),
+                                               GEGL_RECTANGLE(1, 1, 3, 3),
+                                               GEGL_AUTO_ROWSTRIDE,
+                                               NULL,
+                                               NULL);
+
+  linear_d = gegl_buffer_linear_new_from_data (linear_data,
+                                               babl_format ("Y float"),
+                                               GEGL_RECTANGLE(-1, 1, 3, 3),
+                                               GEGL_AUTO_ROWSTRIDE,
+                                               NULL,
+                                               NULL);
+
+  out = gegl_buffer_new (&out_extent, babl_format ("Y float"));
+
+  iter = gegl_buffer_iterator_new (out, &out_extent, 0, NULL,
+                                   GEGL_BUFFER_WRITE, GEGL_ABYSS_NONE);
+
+  gegl_buffer_iterator_add (iter, linear_a, &out_extent, 0, NULL,
+                            GEGL_BUFFER_READ, GEGL_ABYSS_BLACK);
+
+  gegl_buffer_iterator_add (iter, linear_b, &out_extent, 0, NULL,
+                            GEGL_BUFFER_READ, GEGL_ABYSS_BLACK);
+
+  gegl_buffer_iterator_add (iter, linear_c, &out_extent, 0, NULL,
+                            GEGL_BUFFER_READ, GEGL_ABYSS_BLACK);
+
+  gegl_buffer_iterator_add (iter, linear_d, &out_extent, 0, NULL,
+                            GEGL_BUFFER_READ, GEGL_ABYSS_BLACK);
+
+  while (gegl_buffer_iterator_next (iter))
+    {
+      gint ix, iy, pos;
+
+      pos = 0;
+      for (iy = iter->roi[0].y; iy < iter->roi[0].y + iter->roi[0].height; ++iy)
+        for (ix = iter->roi[0].x; ix < iter->roi[0].x + iter->roi[0].width; ++ix)
+          {
+            gfloat **fdata = (gfloat **)iter->data;
+
+            fdata[0][pos] = fdata[1][pos] + fdata[2][pos] + fdata[3][pos] + fdata[4][pos];
+            if (fdata[0][pos] > 1.0f)
+              fdata[0][pos] = 1.0f;
+
+            ++pos;
+          }
+    }
+
+  print_buffer (out);
+  g_object_unref (out);
+  g_object_unref (linear_a);
+  g_object_unref (linear_b);
+  g_object_unref (linear_c);
+  g_object_unref (linear_d);
+  free (linear_data);
+  test_end ();
+}